Error no. 5 after Installing new Zune 80GB battery

I do believe that the error 5 is HDD related, but you can try this. Hold the back button and the up button until you see the Zune logo then let go of the buttons. Should that not work reset your Zune. remember that this will erase all your data. Press and hold the back and up button until the zune logo appears then hold the back,play/pause, and the center button until you see "please wait". you should now restore your Zune with the proper software since you will need the firmware to be reinstalled. since you just worked on your Zune, make sure that all your connections are made and that the cables are seated properly and no bend pins etc have occurred. Again this may work, but I do believe that if it should still fail that you may look toward a new drive. Good Luck and let us know.